diff --git a/dom/promise/PromiseNativeHandler.cpp b/dom/promise/PromiseNativeHandler.cpp
index 5b4b74d41e76..7f29581b0672 100644
--- a/dom/promise/PromiseNativeHandler.cpp
+++ b/dom/promise/PromiseNativeHandler.cpp
@@ -15,51 +15,4 @@ namespace mozilla::dom {
 
 NS_IMPL_ISUPPORTS0(MozPromiseRejectOnDestructionBase)
 
-NS_IMPL_ISUPPORTS0(DomPromiseListener)
-
-DomPromiseListener::DomPromiseListener(CallbackTypeResolved&& aResolve,
-                                       CallbackTypeRejected&& aReject)
-    : mResolve(std::move(aResolve)), mReject(std::move(aReject)) {}
-
-DomPromiseListener::~DomPromiseListener() {
-  if (mReject) {
-    mReject(NS_BINDING_ABORTED);
-  }
-}
-
-void DomPromiseListener::ResolvedCallback(JSContext* aCx,
-                                          JS::Handle<JS::Value> aValue,
-                                          ErrorResult& aRv) {
-  if (mResolve) {
-    mResolve(aCx, aValue);
-  }
-  // Let's clear the lambdas in case we have a cycle to ourselves.
-  Clear();
-}
-
-void DomPromiseListener::RejectedCallback(JSContext* aCx,
-                                          JS::Handle<JS::Value> aValue,
-                                          ErrorResult& aRv) {
-  if (mReject) {
-    nsresult errorCode = NS_ERROR_DOM_NOT_NUMBER_ERR;
-    if (aValue.isInt32()) {
-      errorCode = nsresult(aValue.toInt32());
-    } else if (aValue.isObject()) {
-      RefPtr<::mozilla::dom::DOMException> domException;
-      UNWRAP_OBJECT(DOMException, aValue, domException);
-      if (domException) {
-        errorCode = domException->GetResult();
-      }
-    }
-    mReject(errorCode);
-  }
-  // Let's clear the lambdas in case we have a cycle to ourselves.
-  Clear();
-}
-
-void DomPromiseListener::Clear() {
-  mResolve = nullptr;
-  mReject = nullptr;
-}
-
 }  // namespace mozilla::dom
diff --git a/dom/promise/PromiseNativeHandler.h b/dom/promise/PromiseNativeHandler.h
index 9204488e6fbf..f311f2d29e00 100644
--- a/dom/promise/PromiseNativeHandler.h
+++ b/dom/promise/PromiseNativeHandler.h
@@ -73,32 +73,6 @@ class MozPromiseRejectOnDestruction final
   const char* mCallSite;
 };
 
-// This class is used to set C++ callbacks once a dom Promise a resolved or
-// rejected.
-class DomPromiseListener final : public PromiseNativeHandler {
-  NS_DECL_ISUPPORTS
-
- public:
-  using CallbackTypeResolved =
-      std::function<void(JSContext*, JS::Handle<JS::Value>)>;
-  using CallbackTypeRejected = std::function<void(nsresult)>;
-
-  DomPromiseListener(CallbackTypeResolved&& aResolve,
-                     CallbackTypeRejected&& aReject);
-
-  void Clear();
-
-  void ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue,
-                        ErrorResult& aRv) override;
-  void RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue,
-                        ErrorResult& aRv) override;
-
- private:
-  ~DomPromiseListener();
-  CallbackTypeResolved mResolve;
-  CallbackTypeRejected mReject;
-};
-
 }  // namespace mozilla::dom
 
 #endif  // mozilla_dom_PromiseNativeHandler_h